The present invention relates to a trench rig.
In particular, the present invention relates to a trench rig for excavating monolithic brattices, bases or monolithic areas, to which the description which follows will make specific reference without losing its generality in any way.
Generally, well-known trench rigs of the type described above include a chain-driven excavating tool; a means for transporting the excavating tool itself; and an orientation device, which is suitable for varying the depth at which the tool excavates. These well-known types of trench rigs are generally defined by a hinge with a horizontal axis which is interposed between the tool and the means of transport to rotate, when in use, the tool itself, thus varying the tool""s driving angle, or the excavation depth itself.
In some types of well-known trench rigs, for example the kind described in European Patent No. 0 633 361, the orientation device is replaced by a guide antenna, which is revolvingly mounted on the means of transport, and which supports the already cited excavating tool by means of a sliding slide along the guide antenna itself. In the types of trench rigs which have just been described, the excavating tool usually works in a given operating position, in which the tool itself is driven vertically into the ground, and in which the depth of excavation is varied by sliding the slide along the guide or rather by sliding the tool in relation to the guide antenna.
The trench rig described in the above-mentioned European Patent, while permitting decidedly greater depths of excavation than those reached using trench rigs provided with a hinge, nevertheless presents a number of drawbacks which considerably limit the use of this kind of trench rig. In fact, once the excavation tool is vertically positioned in its operating position, the dimensions of the guide antenna define a considerable bulk in the area above the tool itself, thus limiting the use of the rig in working areas which contain overhead obstacles, such as electrical cables or tunnel vaults.
The aim of the present invention is to realise a trench rig which will resolve the drawbacks described above in a simple and cost-effective manner.
According to the present invention a trench rig comprises an excavating tool presenting a working axis, and means of transport associated with the excavating tool for transporting the excavating tool itself in a given direction; the rig comprising control means which are interposed between the excavating tool and the means of transport for controlling the excavating tool itself around an axis which is transversely orientated to the said working axis and along the working axis itself; the control means comprising clamping means which are selectively engageable directly onto said excavating tool in order to move the excavating tool itself along the working axis.